<template>
	<div class="list" ref="wrapper">
		<div>
			<div class="arer">
				<div class="title border-topbottom">当前城市</div>
				<div class="button-list" >
					<div class="button-wrapper">
						<div class="button">{{this.currentCity}}</div>
					</div>
				</div>
			</div>
			<div class="arer">
				<div class="title border-topbottom">热门城市</div>
				<div class="button-list">
					<div
					class="button-wrapper"
					v-for="item of hotCity"
					:key="item.id"
					@click="handleCityClick(item.name)"
					>
						<div class="button">{{item.name}}</div>
					</div>
				</div>
			</div>
			<div
			class="arer"
			v-for="(item, key) of cities"
			:key="key"
			:ref="key"
			>
				<div class="title border-topbottom">{{key}}</div> <!-- 获取第一次循环数据中的内部数据 -->
				<div
				class="item-list"
				v-for="innerItem of item"
				:key="innerItem.id"
				@click="handleCityClick(innerItem.name)"
				>
					<div class="item border-bottom">{{innerItem.name}}</div>
				</div>
			</div>
		</div>
	</div>
</template>

<script>
import BScroll from 'better-scroll'
import { mapState, mapMutations } from 'vuex'
export default{
	name: 'CityList',
	computed: {
		// ...mapState(['city'])
		...mapState({
			currentCity: 'city' //将vuex里的公用数据city映射到一个名字叫currentCity的计算属性中,
		})
	},
	props: {
		cities: Object,
		hotCity: Array,
		letter: String,
	},
	methods: {
		handleCityClick (city) {
			this.changeCity(city)  //this.$store.commit('changeCity', city),list页和主页city都改变了
			this.$router.push('/')  //然后跳转回主页
			// alert(city)
		},
		...mapMutations(['changeCity'])
	},
	watch: {
		letter: function() {
			// console.log('List监听到的的字母是:',this.letter);
			console.log('滚动到指定的位置-->',this.$refs[this.letter]);// 注意！！！！这个是数组而不是元素节点
			const element = this.$refs[this.letter][0]
			//监听到数组letter的第一个数值（点击alphabet-Z就跳转到list对应的title-Z）
			if(this.letter) {
				this.scroll.scrollToElement(element) //滚动到指定的位置
			}
		}
	},
	//生命周期函数mounted实现滚动效果
	mounted: function() {
		this.scroll = new BScroll(this.$refs.wrapper, {
			click: true
		})
	},
}
</script>

<style lang="stylus" scoped>
	@import '~@/assets/styles/varibles.styl'
	.border-topbottom
		&:before
			border-color: #aaa
		&:after
			border-color: #aaa
	.border-bottom
		&:before
			border-color: #aaa
	.list
		overflow: hidden
		position: absolute
		top: 1.58rem  //显现header部分
		left: 0
		right: 0
		bottom: 0
		// background: orange
		.title
			line-height: .54rem
			background: #eee
			padding-left: .2rem
			color: #666
			font-size: .26rem
		.button-list
			overflow: hidden
			padding: .1rem .6rem .1rem .1rem
			.button-wrapper
				float: left
				width: 33.33%
				.button
					margin: .1rem
					padding: .1rem 0
					text-align: center
					border: .02rem solid #ccc
					border-radius: .06rem
		.item-list
			.item
				line-height: .76rem
				color: #666
				padding-left: .2rem
</style>